Border control has never been a more sensitive issue in peacetime than it now is in Europe and the United States. In Europe, sympathy for people escaping civil war in Syria and state failures in Africa mixes with fear of political violence and social disruption, adding to the already-present stresses of economic austerity.
While technology will not solve the problems driving refugees to seek a better life, it can provide ways to channel them towards official crossing points by sealing off leakier areas, and helping to identify those who might pose real threats. Optronic sensors are key elements of integrated multi-sensor systems, providing automatic detection, identification and classification of targets and minimising false alarms; the last of which significantly alleviates overload on security personnel, Controp marketing and sales vice-president Johnny Carni points out. He also noted a distinct divide developing in the market between low-end and high-end in terms of sensor performance and overall capability. “The market is flooded with (optronics) companies, however not all offer the same level of technology. In fact, only a few companies offer truly high-end technology,” he said. “The competition is fierce, and some of the users choose to settle on less-advanced technologies for various reasons rather than choosing the most advanced systems that can truly solve the problem.”
Israel Aerospace Industries’ Tamam Division’s director of optronics research and development Naveh Bahat, within the company’s Systems, Missiles and Space Group, concurred, adding that some resort to “very, very cheap” cameras bought on Ebay or from Amazon, for example, buying them in large numbers and not worrying too much if some of them fail. He contrasts this with “real borders” monitored with high-performance cameras, some covering short ranges of around half a kilometre (0.3 miles), others with much longer ranges, all connected to image analysis, target recognition and tracking and database systems and software. The high-end systems extend into multiple light wavelengths with visible and short-, medium- and long-wave infrared cameras, uncooled for short ranges and cooled for longer ranges, providing opportunities for image fusion, where images from different sources, or produced by different systems are combined so as to create as detailed an image as possible. Mr. Bahat emphasised that this need not mean fusing or overlaying the images. Instead, fusion would extract the best information from each wavelength to improve tracking performance and vision at longer ranges and in bad weather.
Long Range
Mr. Bahat stressed the importance of stabilisation for long-range cameras, adding that this should be one of the first decisions to make in specifying a border security system. Eric Olson, vice-president for marketing at PureTech Systems, in Arizona, United States, reports an up-tick in the need for very long-range detection in border and coastal surveillance applications. “Part of that increase seems to stem from understanding that these long-range detection capabilities are now achievable at an affordable price point.” He also mentioned growing interest in the use of airborne and ground mobile platforms including vehicles, UAVs (Unmanned Aerial Vehicles) and aerostats to assist border surveillance. The company is most active in the border surveillance markets of North America and the Middle East, and announced in October 2015 that it had completed the initial field deployment of the Remote Video Surveillance System (RVSS) upgrade for the US Customs and Border Protection agency. PureTech provides the software for full motion video, target detection, sensor control and the geospatial user interface as a member of the General Dynamics team that won the RVSS upgrade contract. The RVSS consists of towers mounted in proximity to the US-Mexican frontier to improve border surveillance there.
Arie Chernobrov, general manager of Elbit Systems’ security systems division, emphasised that most of the requirements the company bids for involve the integration of multiple technologies including radar-based automatic detection systems, unattended ground sensors, video motion detector content analysis and verification systems using imaging sensors. Most customers want detection ranges of at least ten kilometres (6.2 miles) for targets, he said. Growing detection ranges bring several challenges that are unique to surveillance applications, Mr. Olson said, citing image instability, environmental interference and the small number of pixels represented by a target. “This challenge is met with increased computing power, software-based stabilisation software, more advanced background modelling and expanded feature extraction, to more accurately identify the target of interest.”
Another challenge is camera barrelling, which is the ability to keep the camera’s centre pixel on the target while zooming in over several kilometres. “A camera with poor barrelling can have a target centred at zero percent zoom, but completely lose sight of that ‘centred’ target as the zoom level increases,” he said. “In addition to more precise mechanical design, video analytics software can also be used to compensate.” Straightforward at short distances, camera control tasks also become harder as range increases, Mr. Olson told Armada. “Simple movements, such as centring a target of interest, slewing to a location or enabling an automatic camera follow at distances of several kilometres become increasing complex as the camera’s pan, tilt and zoom must be controllable in very fine increments.”
Controp emphasises that border surveillance requires optronic systems that enable target classification for quick decision making, arguing that automating classification improves the quality of decisions made and reduces the number of people needed. Furthermore, the use of long-range cameras on towers places even greater demands on stabilisation as towers move in the wind and can shift as parts expand and contract with changes in temperature. The company also notes a growing demand for vehicle-mounted optronic systems. This, said Mr. Carni, brings a need for short, medium and long-range capabilities and multiple sensors on the same platform. At short ranges, a cooled infrared camera is not essential, as an uncooled sensor might suffice. For medium ranges, maximum focal lengths of 250 or 450mm might be enough, while longer ranges need lenses of 720 or 1200 mm. It is important for suppliers to provide a range of systems and capabilities to serve a variety of requirements, some of which result from conditions specific to the border terrain in question, he said. “While detection is usually achieved using a radar, identification and recognition are done by optronic systems. These missions require the highest quality of picture, which can only be attained by an excellent thermal camera with stabilisation.” The company has recently introduced a new system known as 3D-GUARD, which it describes as an advanced three-dimensional video motion detection system. Each 3D-GUARD system is composed of two stationary cameras with fixed fields-of-view and a detection range of up to one kilometre.
Designed to protect strategic facilities and perimeters as well as borders, it is a day and night capable system that detects moving targets and intruders automatically and generates alerts. Providing precise information on target location, size and movement, the 3D-GUARD system acts as reliable ‘virtual fence’ and can be installed on poles or towers, Mr. Carni said, and can operate as a fast deployment system or as a stand-alone solution, and can be controlled from a central command and control system. “The capabilities of this new ‘staring’ system drastically reduce the nuisance of false alarms that are typical of other video analytic systems,” Mr. Carni added.
For long-range automatic detection of movement Controp has developed and recently introduced the TORNADO, which it describes as a passive lightweight fast scanning infrared camera that provides a 360 degree panoramic image. TORNADO uses a Medium Wave Infrared (MWIR) camera and provides panoramic coverage from ground level up to 18 degrees above the horizon, enabling it to detect airborne threats, in particular UAVs. “TORNADO uses unique software algorithms, which automatically detect and track any moving target. It can detect very small targets hundreds of metres away and large targets even tens of kilometres away.” Finally, Controp’s SPEED-LR is a highly-sophisticated, long range, wide-area, passive, real time, stabilized intruder detection system, which automatically detects motion in a wide panoramic view and can be installed on towers, poles, tripods and other supports. Incorporating a long range thermal imaging camera with continuous zoom lens, a colour daylight television camera, eye-safe laser rangefinder and laser pointer, the SPEED-LR can automatically detect, recognise, identify and track any moving target up to tens of kilometres away, says the company.
Long endurance
Finmeccanica stressed that, in addition to adequate range and resolution, optronics for border security must be very reliable for extended periods of remote operation with long maintenance intervals. The company’s Land and Naval Defence Electronics division has developed a new generation of thermal imaging cameras designed to operate unattended for up to 50000 hours. For comparison, says the company, conventional cooled thermal imagers typically require a coolant recharge after 6000 to 9000 operating hours. The extra operating time comes from new cooling engines that the company offers with its latest infrared cameras, including the Horizon.
The company also recently launched a new family of multi-sensor optronics systems under the name NERIO, offering medium-range, long-range and ultra-long-range performance with respective detection ranges of ten kilometres/km, ten to 25km (15.5 miles) and 25 to 50km (31 miles). They comprise a cooled thermal imager, colour television camera and optional laser rangefinder integrated into a gyro-stabilised pan and tilt head, which can be mounted on fixed installations or mobile platforms. The sensor feeds can be integrated into command and control systems or processed locally using Finmeccanica’s VANTAGE or ANTEO software packages.
Choosing spectral bands
Mr. Bahat stressed that the choice of camera for day and night capability is not as simple as might be expected. For example it does not always mean a mix of daylight television and infrared sensors because, depending on the environment, the latter can work as well in daylight as they do in the dark. The choice of infrared wave bands comes next, which depends heavily on local atmospheric characteristics, he said. Mid-wave thermal infrared sensors generally produce sharper images, but long-wave cameras are better at penetrating obscurants and dealing with scenes containing wide temperature variations. Short Wave Infrared (SWIR) offers high resolution and natural-looking black and white images because this portion of the spectrum involves reflected light generated by natural sky-glow, which is present day and night, or from SWIR illuminators. He commented that most customers are fairly conservative in the sensors they prefer. “Most of our customers choose day, night and maybe SWIR systems and they focus on image enhancement and stabilisation.” He added that with SWIR sensors they want to see them working in demonstrations. “SWIR is not a commodity yet, although it has been in the field for 15 years.”
Mr. Bahat pointed to a trend towards multi-wavelength optronics systems for border surveillance applications and his company already offers an open architecture system that can include day television, MWIR and SWIR sensors with integrated laser rangefinder and Global Positioning System geolocation capabilities in the form of its Long Range Reconnaissance and Observation Solution (LOROS). The system encapsulates these sensors in a highly gyro-stabilised turret that can be controlled from ground-based and airborne workstations. Weighing 85kgs (187lbs) and consuming less than 700 Watts of power, the LOROS features automatic target tracking, enhanced image processing and a long-range downlink for both video imagery and data. “Users usually base their decision on cost-effectiveness,” Mr. Carni said. “For short-range missions of up to two kilometres (1.2 miles) they usually choose an uncooled LWIR system, which is less costly. For long-range missions, MWIR would often be the choice. For poor lighting conditions, SWIR would be preferred. In colder climates, they will usually go for cooled LWIR and when recognition of colour is important they chose visible light cameras.”
Finmeccanica concurs with that sensor mix, adding that LWIR sensors are also preferred when there is significant obscuration from smoke or other pollutants to penetrate. However, the company also stresses that advances it has made in its cooled focal plane array detectors (an array of light sensing pixels used to compose a digital image) over the last decade has improved their performance in all environments, to the extent that most of its customers now select MWIR sensors in large formats. “As the demands of detection, recognition and identification ranges have increased, the choice of camera has moved away from uncooled systems into full television (640 x 512 pixels) and increasingly high definition television (1280 x 1024 pixels) sensors,” the company told Armada. Away from Italy, Denmark is home to Copenhagen Sensor Technology, better known as CST. The firm specialises in optronics for defence and homeland security applications, and provides several products suited for border security applications. These include the Spectrel PTZI-1000 which has an in-built laser illuminator which is bore-sighted with the Spectrel PTZI-1000’s pan, tilt and zoom camera enabling the camera’s field-of-view to be illuminated providing detailed night time coverage, as well as day time surveillance.
PureTech’s Mr. Olson also reported demand for visible band cameras for identification purposes, combined with MWIR that, he told Armada, “provides for better target-to-background contrast and more pixels on target at the desired ranges.” He also commented on the growing demand for more esoteric capabilities such as hyperspectral sensing, which combines imaging with spectral analysis that can find spectral signatures of individual materials. This is increasingly used for detecting disturbed ground, which might be a clue to the presence of an insurgent bomb. Meanwhile, Elbit’s Mr. Chernobrov stressed that the camera spectral bands selected are affected by the challenges presented by local environmental conditions, pointing out that conditions in maritime areas are very different from those on borders in deserts or high-altitude mountain regions, and noting that there are also significant variations in humidity, for example, within coastal regions. Other requirements affecting sensor choice include facial recognition, which requires visible light or SWIR cameras, and very long-range detection of military targets at night, which usually moves operators towards cooled MWIR cameras with powerful optics, he said.
All the companies approached for this article said that they regard radar as a complementary technology in these applications, stressing their ability to detect targets in heavy fog, which defeats optronics sensors, and all offer systems that include radar. Furthermore, Mr. Olson said that PureTech is adding geospatial capabilities to its cameras to provide what he called “an extremely robust method for camera-radar collaboration,” enabling both “simple” and “intelligent” slew-to-cue capabilities along with friend-or-foe analysis. Simple slew-to-cue is the ability to point a camera at an exact point in latitude, longitude and elevation. This includes compensation for the speed of a moving target, so the camera does not undershoot. “Intelligent slew-to-cue validates the existence and type of the target using video analytics and then takes actions based on that assessment,” Mr. Olsen continued. “This could involve invoking an automated camera follow, marking the target with a covert laser or invoking a visual or audio deterrent.”
Future trends
Controp’s Mr. Carni pointed to opposing forces affecting the market’s future growth, the first being the burgeoning movement of refugees, on which all agreed, with a possible market restraint caused by lower oil prices affecting security and defence budgets in oil producing countries. In sensor technology terms, Finmeccanica emphasised the continued reduction in camera size, weight and power requirements and cost of ownership, which will make them more accessible to less wealthy nations. According to Mr. Olson, today’s rather piecemeal deployments will move towards collaboration between sensor suites, both static and mobile, with greater information sharing enabling faster, more accurate detections. Mr. Chernobrov said that Elbit is targeting customers who need networked multi-sensor, persistent surveillance systems to control long stretches of border from a single command and control centre. “There are several countries already considering this kind of solution, and in a few years we believe it will become the standard.” Finally, IAI’s Mr. Bahat acknowledged these trends, but with a nod to the late David Bowie’s riff on the ultimate ‘unknowability’ of the future. “I don’t know where I’m going from here, but I promise it won’t be boring.”
by Peter Donaldson
